My requirement is quite simple:

1. Show an organizational hierarchy in a treeview. for example, company -> department1, department2 etc,  Every treenode has a checkbox displayed next to it.
   
2. Whenever the parent node is checked, all its child nodes will get checked as a result of it. I want to handle this event on the server side.
   

Hi,

 In the treeView you can use the TreeNodeCheckChanged event for the checkbox click.

In the MSDN's  TreeView.TreeNodeCheckChanged Event , you could get more inforamtion.

if you find the the treeview could not PostBack, I am afraid you should require javascript. Below is a simple example:

<script language="javascript" type="text/javascript">

function postBackByObject()
{
    var o = window.event.srcElement;
    if (o.tagName == "INPUT" && o.type == "checkbox")
    {
       __doPostBack("","");
    }
}
    </script>

 <asp:TreeView ID="TreeView1" EnableClientScript="true" onclick="javascript:postBackByObject()"  runat="server" DataSourceID="SiteMapDataSource1" LineImagesFolder="~/TreeLineImages" ShowLines="True" OnTreeNodeDataBound="TreeView1_TreeNodeDataBound" OnTreeNodeCheckChanged="TreeView1_TreeNodeCheckChanged" ShowCheckBoxes="All">

 Thanks So much I was stumped on this the javascript works like a charm

 Thanks a lot, Amanda, that will work.

Hi, I have the same problem but this code didn't work for me and I got the warning "Attribute onclick is not a valid attribute of element TreeView"

What might the problem be?

thanks

Amanda, you are awesome. I needed a quick solution to this problem and this worked great.

Thank you, Amanda, for your post, I just would change two little things in order to make it compatible with other navigators (Firefox, etc..):

function postBackByObject(mEvent)
{
    var o;
    // Internet Explorer    
    if (mEvent.srcElement)
    {
        o = mEvent.srcElement;
    }
    // Netscape and Firefox
    else if (mEvent.target)
    {
        o = mEvent.target;
    }
    if (o.tagName == "INPUT" && o.type == "checkbox")
    {
       __doPostBack("","");
    } 
}

and add the event parameter to the fucntion call: onclick="javascript:postBackByObject(event)"

Thanks a lot!

Patrick.

Hi again,

After doing what Amanda suggested, the next step was to wrap my TreeView control with an Ajax UpdatePanel in order to do Asynchronous postbacks and refresh only the Treview control, it was then when I realized that with Ajax I didn't need the Amanda's postBackByObject approach anymore, I just attached a trigger from the UpdatePanel to a hidden button and that's it!, the button will do the Postback. See the code below:

<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">                        
    <ContentTemplate>
         <asp:TreeView ID="TreeViewMenu" runat="server" DataSourceID="XmlDataSourceMenu" ShowCheckBoxes="All" BorderWidth="3px" BorderColor="White" NodeStyle-ForeColor="#5982A2" OnTreeNodeDataBound="TreeViewMenu_TreeNodeDataBound" OnPreRender="TreeViewMenu_PreRender" OnTreeNodeCheckChanged="TreeViewMenu_TreeNodeCheckChanged">
                <DataBindings>                            
                     <asp:TreeNodeBinding DataMember="Menu" TextField="Name" Depth="0" SelectAction="None" ValueField="Id" />
                      <asp:TreeNodeBinding DataMember="Submenu" TextField="Name" Depth="1" SelectAction="None" ValueField="Id" />
                </DataBindings>
                <NodeStyle ForeColor="#5982A2" />
         </asp:TreeView>
         <asp:XmlDataSource ID="XmlDataSourceMenu" runat="server" DataFile="~/_resources/Menu.xml" XPath="//Menu" TransformFile="~/_resources/Menu.xslt">
         </asp:XmlDataSource>
   </ContentTemplate>
   <Triggers>
      <asp:AsyncPostBackTrigger ControlID="buttonCheck" EventName="click" />
   </Triggers>
</asp:UpdatePanel>

<asp:button ID="buttonCheck" runat="server" CausesValidation="false" />

and the code behind is:

buttonCheck.Attributes.CssStyle["visibility"] = "hidden";
TreeViewMenu.Attributes.Add("onclick", string.Format("document.getElementById('{0}').click();", buttonCheck.ClientID));

 Of course there is no need to say that you must have an ScriptManager control for Ajax to work.

Patrick.

Hi amanda and patrick,

Thanks a lot

I was facing this same problem of treeview.

I had tried out with what you both had suggested. And its working perfectly fine.

I am now using the code that patric had suggested since it doesn't not flash the page due to ajax.

Thanks again

Omkar